1. Field of the Invention
The present invention relates to a process for the preparation of a synthetic resin film having insect repelling/killing abilities, in which fenitrothion is used as insect repellent/killer.
2. Description of the Prior Art
Films having insect repelling/killing abilities are used for wrapping fruits when they are transported, for wrapping clothes, or as underlay for tatami or carpet, effectively protecting fruits or clothes from insect damage and preventing the growth of mite under tatami or carpet.
Films having insect repelling/killing abilities can be largely classified into two groups, i.e. those prepared by interleaving a lamination of synthetic resin sheets or paper with an insect repellent/killer, and those prepared by applying an insect repellent/killer on synthetic resin sheets or paper, or impregnating them with an insect repellent/killer.
Those prepared by interleaving a lamination with an insect repellent/killer are limited in the reduction of its thickness, so that it cannot be formed into thin film.
On the other hand, those prepared by applying an insecticide on synthetic resin sheets or paper exert an insect repelling/killing effect only in a short period because the insecticide applied on the surface of the substrate is directly exposed to outside. It is difficult to impregnate synthetic resin with an insecticide, although paper can be impregnated. It has not been attempted so far to incorporate an insecticide with a synthetic resin material when the resin is molded and to form it into film.
Under these circumstances, it has been expected to develop a product which can be molded into film, in which an insecticide is incorporated with a synthetic resin material, characterized in that the obtained film shows not only a homogeneous but also prolonged insect repelling/killing effect, in such a manner that the insecticide appropriately bleed to the surface of the film.